The steel industry has relied on a process that has been in use for many years for the conversion of iron ore into steel. The process converts iron ore into pig iron in a blast furnace using coke produced in a coke oven. The process next converts the pig iron or hot metal into steel in an open hearth or basic oxygen furnace.
In recent years, federal and local environmental regulations have caused numerous problems for steel producers using this steel-making process. The blast furnace and coke ovens used in the process are not only energy intensive but also responsible for most environmentally damaging emissions by steel producers. To redesign or modify blast furnaces and coke ovens to comply with pollution standards is expensive. The expense would cause the cost of steel produced by the conventional steel-making process to be non-competitive with steel produced by foreign competitors.
To address these problems, a process was developed for steel production that eliminates the blast furnace and coke oven in the steel-making process. In the process, a bed of iron oxide is fluidized by a single, multiple-component gas stream and directly converted into an iron carbide-containing product, primarily consisting of Fe.sub.3 C. The iron carbide is then added to a basic oxygen or electric arc furnace to produce steel. In the process, reduction and carburization reactions occur together in the same fluidized bed.
Another process has been applied to produce acicular iron carbides having desired magnetic characteristics for use in magnetic recording and as catalysts for converting CO and H.sub.2 into lower aliphatic hydrocarbons. In the process, a bed of the acicular iron oxide is reduced by one gas and a bed of the reduced product is then carburized by another gas to produce acicular iron carbides. The process suffers from slow reaction kinetics and large amounts of impurities (including iron oxide, free carbon and metallic iron) in the acicular iron carbide product.
Other techniques to convert an iron-containing feed material into an iron carbide-containing product are batch processes, require expensive components and/or otherwise raise other operational complications.
It would be advantageous to provide a continuous process to convert iron-containing materials into iron carbide. It would be further advantageous to produce an iron carbide product with environmentally friendly and/or non-hazardous byproducts. It would be a further advantage to optimize the reaction kinetics of chemical reactions to convert iron-containing materials into iron carbide and to produce an iron carbide product that has high purity.
Additionally, it would be advantageous to develop an environmentally friendly, energy efficient and inexpensive process to produce steel. It would be further advantageous to convert, inexpensively and efficiently, iron-containing materials into iron carbide for use in the production of steel. It would be a further advantage to eliminate the blast furnace and coke oven from the steel-making process.